Identifier

Author

Degree

Doctor of Philosophy (PhD)

Department

School of Animal Science

Document Type

Dissertation

Abstract

Detection of estrus in white-tailed (WT) deer is laborious and often missed, as there are few visual cues presented during the 24 h period in which females are receptive to mating. Reproductive management of WT operations is improved by the use of fixed-timed artificial insemination (FTAI) protocols. Fixed-timed AI removes the need for estrus detection and ensures the breeding of an entire herd, as well as the ability to schedule fawning within predetermined timeframes. Two studies evaluated two FTAI regimens and their ability to synchronize estrous in WT. The first study implemented the administration of eCG 200 IU (im) at progesterone device removal (CIDR-g), which had been present for 14 d, followed by FTAI 60 h post-CIDR-g removal. Finding from this study demonstrated that eCG given at CIDR removal did not affect pregnancy rates, nor did the fecundity rates of does pregnant to FTAI differ from does pregnant from natural mating. Does that were inseminated ¡Ý60.5 h after CIDR-g removal were 22 times more likely to become pregnant following FTAI than does which were inseminated ¡Ü60.5 h post-CIDR-g removal. The second study evaluated the effect of GnRH administered at insemination on pregnancy rates following a 14 d CIDR-g regimen. Similar to the previous study, does inseminated beyond 60.5 h post-CIDR-g withdrawal were four times more likely to become pregnant to FTAI. The odds of pregnancy also increased 5 times when does were treated with GnRH. However, the pregnancy rates from this study were lower than those when eCG was given at CIDR-g withdrawal. In addition to improving WT estrous synchronization, FTAI can lead to further improvements in WT in vitro production and propagation of desired genetics throughout a herd. The third study evaluated the chemical components of two in vitro fertilization media (BIVF and DSOF) and their ability to induce capacitation and the acrosome reaction in WT epididymal spermatozoa. Induction of lipid disorder was more likely when spermatozoa were in the presence of BIVF than DSOF. Additionally, when compared to supplementation of sheep serum, heparin in BIVF was more likely to improve capacitation rates. However, higher levels of calcium concentrations in DSOF were twice as likely to induce the acrosome reaction (AR).